target-xtensa: implement ATOMCTL SR

ATOMCTL SR controls s32c1i opcode behavior depending on targeted memory
type. See ISA, 4.3.12.4 for details.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

target-xtensa/cpu.c

@@ -48,6 +48,8 @@ static void xtensa_cpu_reset(CPUState *s)
             XTENSA_OPTION_INTERRUPT) ? 0x1f : 0x10;
     env->sregs[VECBASE] = env->config->vecbase;
     env->sregs[IBREAKENABLE] = 0;
+    env->sregs[ATOMCTL] = xtensa_option_enabled(env->config,
+            XTENSA_OPTION_ATOMCTL) ? 0x28 : 0x15;
 
     env->pending_irq_level = 0;
     reset_mmu(env);

target-xtensa/cpu.h

@@ -65,6 +65,7 @@ enum {
     XTENSA_OPTION_FP_COPROCESSOR,
     XTENSA_OPTION_MP_SYNCHRO,
     XTENSA_OPTION_CONDITIONAL_STORE,
+    XTENSA_OPTION_ATOMCTL,
 
     /* Interrupts and exceptions */
     XTENSA_OPTION_EXCEPTION,
@@ -128,6 +129,7 @@ enum {
     ITLBCFG = 91,
     DTLBCFG = 92,
     IBREAKENABLE = 96,
+    ATOMCTL = 99,
     IBREAKA = 128,
     DBREAKA = 144,
     DBREAKC = 160,
@@ -193,6 +195,14 @@ enum {
 
 #define REGION_PAGE_MASK 0xe0000000
 
+#define PAGE_CACHE_MASK    0x700
+#define PAGE_CACHE_SHIFT   8
+#define PAGE_CACHE_INVALID 0x000
+#define PAGE_CACHE_BYPASS  0x100
+#define PAGE_CACHE_WT      0x200
+#define PAGE_CACHE_WB      0x400
+#define PAGE_CACHE_ISOLATE 0x600
+
 enum {
     /* Static vectors */
     EXC_RESET,

target-xtensa/helper.c

@@ -390,6 +390,7 @@ int xtensa_tlb_lookup(const CPUXtensaState *env, uint32_t addr, bool dtlb,
 static unsigned mmu_attr_to_access(uint32_t attr)
 {
     unsigned access = 0;
+
     if (attr < 12) {
         access |= PAGE_READ;
         if (attr & 0x1) {
@@ -398,8 +399,22 @@ static unsigned mmu_attr_to_access(uint32_t attr)
         if (attr & 0x2) {
             access |= PAGE_WRITE;
         }
+
+        switch (attr & 0xc) {
+        case 0:
+            access |= PAGE_CACHE_BYPASS;
+            break;
+
+        case 4:
+            access |= PAGE_CACHE_WB;
+            break;
+
+        case 8:
+            access |= PAGE_CACHE_WT;
+            break;
+        }
     } else if (attr == 13) {
-        access |= PAGE_READ | PAGE_WRITE;
+        access |= PAGE_READ | PAGE_WRITE | PAGE_CACHE_ISOLATE;
     }
     return access;
 }
@@ -410,14 +425,17 @@ static unsigned mmu_attr_to_access(uint32_t attr)
  */
 static unsigned region_attr_to_access(uint32_t attr)
 {
-    unsigned access = 0;
-    if ((attr < 6 && attr != 3) || attr == 14) {
-        access |= PAGE_READ | PAGE_WRITE;
-    }
-    if (attr > 0 && attr < 6) {
-        access |= PAGE_EXEC;
-    }
-    return access;
+    static const unsigned access[16] = {
+         [0] = PAGE_READ | PAGE_WRITE             | PAGE_CACHE_WT,
+         [1] = PAGE_READ | PAGE_WRITE | PAGE_EXEC | PAGE_CACHE_WT,
+         [2] = PAGE_READ | PAGE_WRITE | PAGE_EXEC | PAGE_CACHE_BYPASS,
+         [3] =                          PAGE_EXEC | PAGE_CACHE_WB,
+         [4] = PAGE_READ | PAGE_WRITE | PAGE_EXEC | PAGE_CACHE_WB,
+         [5] = PAGE_READ | PAGE_WRITE | PAGE_EXEC | PAGE_CACHE_WB,
+        [14] = PAGE_READ | PAGE_WRITE             | PAGE_CACHE_ISOLATE,
+    };
+
+    return access[attr & 0xf];
 }
 
 static bool is_access_granted(unsigned access, int is_write)
@@ -566,7 +584,7 @@ int xtensa_get_physical_addr(CPUXtensaState *env, bool update_tlb,
     } else {
         *paddr = vaddr;
         *page_size = TARGET_PAGE_SIZE;
-        *access = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
+        *access = PAGE_READ | PAGE_WRITE | PAGE_EXEC | PAGE_CACHE_BYPASS;
         return 0;
     }
 }
@@ -599,24 +617,34 @@ static void dump_tlb(FILE *f, fprintf_function cpu_fprintf,
                 xtensa_tlb_get_entry(env, dtlb, wi, ei);
 
             if (entry->asid) {
+                static const char * const cache_text[8] = {
+                    [PAGE_CACHE_BYPASS >> PAGE_CACHE_SHIFT] = "Bypass",
+                    [PAGE_CACHE_WT >> PAGE_CACHE_SHIFT] = "WT",
+                    [PAGE_CACHE_WB >> PAGE_CACHE_SHIFT] = "WB",
+                    [PAGE_CACHE_ISOLATE >> PAGE_CACHE_SHIFT] = "Isolate",
+                };
                 unsigned access = attr_to_access(entry->attr);
+                unsigned cache_idx = (access & PAGE_CACHE_MASK) >>
+                    PAGE_CACHE_SHIFT;
 
                 if (print_header) {
                     print_header = false;
                     cpu_fprintf(f, "Way %u (%d %s)\n", wi, sz, sz_text);
                     cpu_fprintf(f,
-                            "\tVaddr       Paddr       ASID  Attr RWX\n"
-                            "\t----------  ----------  ----  ---- ---\n");
+                            "\tVaddr       Paddr       ASID  Attr RWX Cache\n"
+                            "\t----------  ----------  ----  ---- --- -------\n");
                 }
                 cpu_fprintf(f,
-                        "\t0x%08x  0x%08x  0x%02x  0x%02x %c%c%c\n",
+                        "\t0x%08x  0x%08x  0x%02x  0x%02x %c%c%c %-7s\n",
                         entry->vaddr,
                         entry->paddr,
                         entry->asid,
                         entry->attr,
                         (access & PAGE_READ) ? 'R' : '-',
                         (access & PAGE_WRITE) ? 'W' : '-',
-                        (access & PAGE_EXEC) ? 'X' : '-');
+                        (access & PAGE_EXEC) ? 'X' : '-',
+                        cache_text[cache_idx] ? cache_text[cache_idx] :
+                            "Invalid");
             }
         }
     }

target-xtensa/helper.h

@@ -23,6 +23,7 @@ DEF_HELPER_3(waiti, void, env, i32, i32)
 DEF_HELPER_3(timer_irq, void, env, i32, i32)
 DEF_HELPER_2(advance_ccount, void, env, i32)
 DEF_HELPER_1(check_interrupts, void, env)
+DEF_HELPER_3(check_atomctl, void, env, i32, i32)
 
 DEF_HELPER_2(wsr_rasid, void, env, i32)
 DEF_HELPER_FLAGS_3(rtlb0, TCG_CALL_NO_RWG_SE, i32, env, i32, i32)

target-xtensa/op_helper.c

@@ -415,6 +415,63 @@ void HELPER(check_interrupts)(CPUXtensaState *env)
     check_interrupts(env);
 }
 
+/*!
+ * Check vaddr accessibility/cache attributes and raise an exception if
+ * specified by the ATOMCTL SR.
+ *
+ * Note: local memory exclusion is not implemented
+ */
+void HELPER(check_atomctl)(CPUXtensaState *env, uint32_t pc, uint32_t vaddr)
+{
+    uint32_t paddr, page_size, access;
+    uint32_t atomctl = env->sregs[ATOMCTL];
+    int rc = xtensa_get_physical_addr(env, true, vaddr, 1,
+            xtensa_get_cring(env), &paddr, &page_size, &access);
+
+    /*
+     * s32c1i never causes LOAD_PROHIBITED_CAUSE exceptions,
+     * see opcode description in the ISA
+     */
+    if (rc == 0 &&
+            (access & (PAGE_READ | PAGE_WRITE)) != (PAGE_READ | PAGE_WRITE)) {
+        rc = STORE_PROHIBITED_CAUSE;
+    }
+
+    if (rc) {
+        HELPER(exception_cause_vaddr)(env, pc, rc, vaddr);
+    }
+
+    /*
+     * When data cache is not configured use ATOMCTL bypass field.
+     * See ISA, 4.3.12.4 The Atomic Operation Control Register (ATOMCTL)
+     * under the Conditional Store Option.
+     */
+    if (!xtensa_option_enabled(env->config, XTENSA_OPTION_DCACHE)) {
+        access = PAGE_CACHE_BYPASS;
+    }
+
+    switch (access & PAGE_CACHE_MASK) {
+    case PAGE_CACHE_WB:
+        atomctl >>= 2;
+    case PAGE_CACHE_WT:
+        atomctl >>= 2;
+    case PAGE_CACHE_BYPASS:
+        if ((atomctl & 0x3) == 0) {
+            HELPER(exception_cause_vaddr)(env, pc,
+                    LOAD_STORE_ERROR_CAUSE, vaddr);
+        }
+        break;
+
+    case PAGE_CACHE_ISOLATE:
+        HELPER(exception_cause_vaddr)(env, pc,
+                LOAD_STORE_ERROR_CAUSE, vaddr);
+        break;
+
+    default:
+        break;
+    }
+}
+
 void HELPER(wsr_rasid)(CPUXtensaState *env, uint32_t v)
 {
     v = (v & 0xffffff00) | 0x1;

target-xtensa/overlay_tool.h

@@ -42,6 +42,10 @@
 #define XCHAL_VECBASE_RESET_VADDR 0
 #endif
 
+#ifndef XCHAL_HW_MIN_VERSION
+#define XCHAL_HW_MIN_VERSION 0
+#endif
+
 #define XCHAL_OPTION(xchal, qemu) ((xchal) ? XTENSA_OPTION_BIT(qemu) : 0)
 
 #define XTENSA_OPTIONS ( \
@@ -62,6 +66,8 @@
     XCHAL_OPTION(XCHAL_HAVE_FP, XTENSA_OPTION_FP_COPROCESSOR) | \
     XCHAL_OPTION(XCHAL_HAVE_RELEASE_SYNC, XTENSA_OPTION_MP_SYNCHRO) | \
     XCHAL_OPTION(XCHAL_HAVE_S32C1I, XTENSA_OPTION_CONDITIONAL_STORE) | \
+    XCHAL_OPTION(XCHAL_HAVE_S32C1I && XCHAL_HW_MIN_VERSION >= 230000, \
+        XTENSA_OPTION_ATOMCTL) | \
     /* Interrupts and exceptions */ \
     XCHAL_OPTION(XCHAL_HAVE_EXCEPTIONS, XTENSA_OPTION_EXCEPTION) | \
     XCHAL_OPTION(XCHAL_HAVE_VECBASE, XTENSA_OPTION_RELOCATABLE_VECTOR) | \

target-xtensa/translate.c

@@ -99,6 +99,7 @@ static const char * const sregnames[256] = {
     [ITLBCFG] = "ITLBCFG",
     [DTLBCFG] = "DTLBCFG",
     [IBREAKENABLE] = "IBREAKENABLE",
+    [ATOMCTL] = "ATOMCTL",
     [IBREAKA] = "IBREAKA0",
     [IBREAKA + 1] = "IBREAKA1",
     [DBREAKA] = "DBREAKA0",
@@ -556,6 +557,11 @@ static void gen_wsr_ibreakenable(DisasContext *dc, uint32_t sr, TCGv_i32 v)
     gen_jumpi_check_loop_end(dc, 0);
 }
 
+static void gen_wsr_atomctl(DisasContext *dc, uint32_t sr, TCGv_i32 v)
+{
+    tcg_gen_andi_i32(cpu_SR[sr], v, 0x3f);
+}
+
 static void gen_wsr_ibreaka(DisasContext *dc, uint32_t sr, TCGv_i32 v)
 {
     unsigned id = sr - IBREAKA;
@@ -693,6 +699,7 @@ static void gen_wsr(DisasContext *dc, uint32_t sr, TCGv_i32 s)
         [ITLBCFG] = gen_wsr_tlbcfg,
         [DTLBCFG] = gen_wsr_tlbcfg,
         [IBREAKENABLE] = gen_wsr_ibreakenable,
+        [ATOMCTL] = gen_wsr_atomctl,
         [IBREAKA] = gen_wsr_ibreaka,
         [IBREAKA + 1] = gen_wsr_ibreaka,
         [DBREAKA] = gen_wsr_dbreaka,
@@ -2317,10 +2324,15 @@ static void disas_xtensa_insn(CPUXtensaState *env, DisasContext *dc)
                 int label = gen_new_label();
                 TCGv_i32 tmp = tcg_temp_local_new_i32();
                 TCGv_i32 addr = tcg_temp_local_new_i32();
+                TCGv_i32 tpc;
 
                 tcg_gen_mov_i32(tmp, cpu_R[RRI8_T]);
                 tcg_gen_addi_i32(addr, cpu_R[RRI8_S], RRI8_IMM8 << 2);
                 gen_load_store_alignment(dc, 2, addr, true);
+
+                gen_advance_ccount(dc);
+                tpc = tcg_const_i32(dc->pc);
+                gen_helper_check_atomctl(cpu_env, tpc, addr);
                 tcg_gen_qemu_ld32u(cpu_R[RRI8_T], addr, dc->cring);
                 tcg_gen_brcond_i32(TCG_COND_NE, cpu_R[RRI8_T],
                         cpu_SR[SCOMPARE1], label);
@@ -2328,6 +2340,7 @@ static void disas_xtensa_insn(CPUXtensaState *env, DisasContext *dc)
                 tcg_gen_qemu_st32(tmp, addr, dc->cring);
 
                 gen_set_label(label);
+                tcg_temp_free(tpc);
                 tcg_temp_free(addr);
                 tcg_temp_free(tmp);
             }